Field of the Disclosure
The present disclosure is related to syringes for use in the medical field and, more particularly, to syringes used in the medical field where the syringe includes a rolling diaphragm for selectively filling the syringe with a fluid and discharging the fluid from the syringe.
Description of Related Art
In many medical diagnostic and therapeutic procedures, a medical practitioner, such as a physician, injects a patient with one or more medical fluids. In recent years, a number of injector-actuated syringes and fluid injectors for pressurized injection of medical fluids, such as a contrast solution (often referred to simply as “contrast”), a flushing agent, such as saline, and other medical fluids, have been developed for use in procedures such as angiography, computed tomography (CT), ultrasound, magnetic resonance imaging (MRI), positron emission tomography (PET), and other molecular imaging procedures. In general, these fluid injectors are designed to deliver a preset amount of fluid at a preset pressure and/or flow rate.
In some injection procedures, the medical practitioner places a catheter or a needle connected to tubing, or other fluid delivery connection into a vein or artery of the patient. The catheter or the tubing is connected to either a manual or to an automatic fluid injection mechanism. Automatic fluid injection mechanisms typically include at least one syringe connected to at least one fluid injector having, for example, at least one powered linear piston. The at least one syringe includes, for example, a source of contrast and/or a source of flushing fluid. The medical practitioner enters settings into an electronic control system of the fluid injector for a fixed volume of contrast and/or saline and a fixed rate of injection for each.
The injected contrast and/or saline are delivered to a patient's vasculature through the catheter or needle inserted into the patient's body, such as the patient's arm or groin area. A dose of contrast is referred to as a bolus. Once the bolus of contrast is delivered to the desired site, that area is imaged using a conventional imaging technique, such as angiography imaging or scanning, CT, ultrasound, MRI, PET, and other molecular imaging procedures. The presence of the contrast becomes clearly visible against the background of the surrounding tissue.
A number of injector-actuated syringes and powered injectors for use in medical procedures have been developed. Typically, injectors have drive members, such as pistons, that connect to a syringe plunger. The syringe generally includes a rigid barrel with the syringe plunger being slidably disposed within the barrel. The drive members drive the plungers in a proximal and/or distal direction relative to a longitudinal axis of the barrel to aspirate a fluid into the syringe barrel or deliver the fluid from the syringe barrel.
It is well known that syringes used in the medical field are typically disposable and are discarded after one use. Although disposable syringes are typically made by mass production methods such as injection molding, such disposable syringes are relatively expensive due to the materials and precision involved in their manufacture. Accordingly, it remains desirable to develop improved designs of syringes to facilitate injection procedures.